Log Message:
x11/citron: update to 0.15.0

v0.15.0

battery: add '%S' specifier for displaying battery status through a symbol
 -This specifier is inspired by Emacs' battery-mode-line-format '%b' specifier.

 -Other minor changes:
  -The conditions which decide upon which battery icon to display depending on
   the battery percentage have been decremented by 1.
   -This means that if your battery's percentage is 20%, you'll be shown a
    battery-level-20-discharging-symbolic icon instead of
    battery-level-10-discharging-symbolic icon.

 -Bump dependencies to their latest versions.